Morphology of small fresh craters on the Moon may reflect target properties, and the related studies are significant for selection of the landing sites in future missions. Among the morphological characteristics of small fresh craters, the depth-to-diameter is the most important and has been widely studied in previous research. In this research, with the recently acquired high resolution images by LRO mission, we expand the study into the small fresh crater with their diameter in sub-kilometer or even tens of meters. The results show that, relative to the larger craters with their diameter larger than 1 km, the ratio of the small craters decrees from ~0.2 to ~0.1, whether they are in lunar mares or in highlands. The lower ratio is possibly resulted by the low strength of the target for the small craters, and the detailed mechanism should be further studied in future.